Conventional systems composed of electronic devices represented by an audio-video processing apparatus, include a system in which one electronic device receives menu information of another electronic device connected via a network or the like, and merges such received menu information with its own menu information (for example, refer to Japanese Laid-Open Patent Application No. 07-177586 (page 1, FIG. 1, and the like) and Japanese Laid-Open Patent Application No. 2003-029895 (page 1, FIG. 1, and the like)). Such electronic device system is capable of controlling the operation of another electronic device connected, using such merged menu information.
However, in the above-mentioned conventional electronic device system, menu items of an electronic device which has become unusable due to such reasons as that it has been powered off, are displayed as menu items in the merged menu information, meaning that menu items which are substantially unnecessary are displayed. Due to an increased number of unnecessary menu items, a user needs to spend a longer time to find a menu item s/he wishes to select or is unable to find a desired menu item. This poses a problem of poor operability.
Furthermore, the above-mentioned conventional electronic device system also has a problem of complicated operation and poor operability since the user needs to manipulate the electronic devices separately by, for example, checking which electronic devices are in a state ready to be manipulated, by determining an electronic device to manipulate from the electronic devices that are in a state ready to be manipulated, and by selecting menu items corresponding to the respective electronic devices.
In particular, since audio-video processing apparatuses such as televisions have become more diverse in function in recent years, there is a strong demand for improved operability of such audio-video processing apparatuses.